The most satisfactory method of replacing brake lining is to install new shoe and lining assemblies. This insures brake shoes that are not distorted through use, and linings properly riveted to shoes and ground to correct radius by accurate factory machinery.

Each brake shoe and lining set listed under Group 5.017 contains two primary and two secondary shoe and lining assemblies, enough for two wheels. Sets are available in standard size and also in .030″ oversize for use where brake drums have been rebored.

Use brake shoe lining sets listed under Group 5.018 if the old brake shoes are to be relined. Each lining set contains two primary and two secondary linings, enough for two wheels. Linings are shaped, drilled, and ground to correct thickness and radius, and are packaged with enough rivets for installation on shoes. Linings sets are available in standard and .030″ oversizes.

Two optional types of primary and secondary brake shoe lining material are approved for production and service. Because these materials have slightly different braking characteristics, primary and secondary linings must be of same type in each brake assembly. These different types cannot be distinguished by inspection; however, a carton of linings or shoes contains only one type of material.

To insure equal braking action it is essential that left and right brake assemblies at either end of car contain the same type of lining material. It is not necessary, however, that front and rear brake assemblies contain the same type of material. When replacing linings or shoes install contents of one carton on left and right sides at same end of car-do not install contents of one carton in front and rear brake assemblies.

The following procedure covers 1950 Buick brake replacement of shoe and lining assemblies and also relining of old shoes at any one wheel. Additional operations are specified where inspection may indicate their need. Each additional operation is identified by an asterisk ( *) preceding the reference to paragraph number covering the operation.

Removal and Inspection

  1. Jack up car in a safe manner, remove wheel, then remove brake drum (rear) or drum and hub assembly (front). NOTE: Since stops are located on brake backing plate to prevent pistons from leaving wheel cylinder, it is not necessary to install wheel cylinder clamps when drums are removed; however, brake pedal must not be operated while drum is removed.
  2. Unhook shoe return springs from anchor pin, using large pliers and being careful not to nick or distort springs. Remove shoe hold down springs, spread shoes to clear wheel cylinder connecting links, remove parking brake strut (rear only), and remove shoes from backing plate. Disconnect cable from parking brake lever (rear only). See figure 8-11.
    1950 Buick Rear Wheel Brake Assembly-Right

    1950 Buick Rear Wheel Brake Assembly-Right

  3. Separate the brake shoes by removing adjusting screw and lock spring. Remove parking brake lever from secondary brake shoe (rear lever (rear only). See figure 8-11.
  4. Clean all dirt out of brake drum, using care to avoid getting dirt into front wheel bearings. Inspect drums and replace or recondition if required (*par. 8-17). If front drum and hub is removed, inspect wheel bearings and oil seal packings and replace faulty parts (*par. 6-14).
  5. Carefully pull lower edges of wheel cylinder boots away from cylinders and note whether interior is wet with brake fluid. Fluid at this point indicates leakage past piston cup, requiring overhaul of wheel cylinder (*par. 8-18).
  6. If working at rear wheels, inspect backing plate for oil leak past wheel bearing oil seals. Correct any leak by installation of new seals (*par. 5-9).
  7. Check all backing plate attaching bolts to make sure they are tight. Clean all rust and dirt from shoe contact surfaces on plate, using fine emery cloth.

Relining Brake Shoes

If old brake shoes are to be relined, inspect shoes for distortion and for looseness between the rim and web; these are causes for discarding any shoe. If shoes are serviceable, be governed by the following points in installing new linings:

  1. Remove old linings by drilling out rivets. Punching rivets out will distort shoe rim. Thoroughly clean surface of shoe rim and file off any burrs or high spots.
  2. Use only genuine Buick brake lining and the rivets included in lining package which are of correct size. The rivets must fit the holes and the solid body of rivet should extend through the shoe rim, but no farther.
  3. Keep hands clean while handling brake lining. Do not permit oil or grease to come in contact with lining.
  4. Start the riveting at center of shoe and lining and work toward the ends. Use a roll set for riveting; a star set might split the tubular end and then the rivet would not fill the hole. The primary lining is shorter than secondary lining, therefore the rivet holes at each end of shoe rim are not used.
  5. After riveting is completed, lining must seat snugly against shoe with no more than .005″ separation midway between rivets. Check with a .004″ (permissable) and a .006″ (no go) feeler gauge.
  6. It is not necessary to grind Buick linings after installation on shoes as linings are correctly ground in production. It is advisable, however, to place shoes in drum and check for proper arc and fit in drum, using feeler gauges. No more than .004″ clearance should exist between lining and drum at any point.

Installation and Adjustment

  1. If working on rear brakes, lubricate parking brake cable (par. 8-14).
  2. On rear brakes only, lubricate fulcrum end of parking brake lever and the bolt with Bendix or Delco Brake Lubricant, or Lubriplate, then attach lever to secondary shoe with bolt, spring washer, nut, and Pal nut. Make sure that lever is free moving. See figure 8-11.
  3. Connect brake shoes together with lock spring, then place adjusting screw, socket, and nut in position. The socket and star wheel must be adjacent to primary shoe on front brake, and adjacent to secondary shoe on rear brake.
  4. Attach brake shoes to backing plate with hold down springs, pins, and cups, at the same time engaging shoes with wheel cylinder connecting links. The primary shoe (short lining) goes forward. On rear brakes, connect cable to parking brake lever and install strut between lever and primary shoe as installation is made. See figure 8-11.
  5. If old brake shoe return springs are nicked, distorted, or if doubtful strength it is advisable to install new ones. Hook springs in shoes and over end of anchor pin, using large pliers and being careful not to nick or distort springs.
  6. Pry shoes away from backing plate and lubricate shoe contact surfaces with a thin coating of Bendix or Delco Brake Lubricant, or Lubriplate. On rear brakes, sparingly apply same lubricant where brake cable contacts backing plate.
  7. Install brake drum and wheel. If working on front brake lubricate and adjust front wheel bearings (par. 6-14). Remove adjusting hole cover from backing plate.
  8. Centralize brake shoes and set anchor pin, then adjust all brake shoes and brake cable as described in paragraph 8-15, steps 17 through 22.

IMPORTANT: Brakes must not be severely applied immediately after installation of new brake shoes or linings. Severe application may permanently injure new linings and may score brake drums. When linings are new they must be given moderate use for several days until nicely burnished.



Whenever brake drums are removed they should be thoroughly cleaned and inspected for cracks, scores, deep grooves, and out-of-round. Any of these conditions must be corrected since they can impair the efficiency of brake operation and also can cause premature failure of other parts.

Cracked Drum

A cracked drum is unsafe for further service and must be replaced. Welding a cracked drum is not recommended.

Scored Drum

Smooth up any slight scores by polishing with fine emery cloth. Heavy or extensive scoring will cause excessive brake lining wear and it will probably be necessary to rebore in order to true up the braking surface.

Grooved Drum

If the brake linings are little worn and drum is grooved, the drum should be rebored just enough to remove grooves and the ridges in the lining should be lightly removed with a lining grinder.

If brake linings are more than half worn, but do not need replacement, the drum should be polished with fine emery cloth but should not be rebored. At this stage, eliminating the grooves in drum and smoothing the ridges on lining would necessitate removal of too much metal and lining, while if left alone, the grooves and ridges match and satisfactory service can be obtained.

If brake linings are to be replaced, a grooved drum should be rebored for use with oversize linings (subpar. e, below). A grooved drum, if used with new lining, will not only wear the lining but will make it difficult, if not impossible, to obtain efficient brake performance.

Out-of-Round Drum

An out-of-round drum makes accurate brake shoe adjustment impossible and is likely to cause excessive wear of other parts of brake mechanism due to its eccentric action. An out of-round drum can also cause severe and very irregular tire tread wear.

A drum that is more than .010″ out-of-round on the diameter is unfit for service and should be rebored (subpar. e, below). Out-of-round as well as taper and wear can be accurately measured with an inside micrometer fitted with proper extension rods.

When measuring a drum for out-of-round, taper, and wear, take measurements at the open and closed edges of machined surface and at right angles to each other. Figure 8-12 gives the machining specifications for a standard brake drum, which will aid in determining the condition of drum being inspected.